For decades, it has been drilled into us to slop on sunscreen and cover up to stay safe in the sun, but there's increasing support for showing some skin for at least part of the day.
The sun’s ultraviolet (UV) rays remain the primary risk factor for developing skin cancer and also contribute to premature aging and hyperpigmentation, but scientists are increasingly examining what’s on the brighter side of sun exposure.
Turns out, small amounts of the same sunburn- and wrinkle-causing wavelengths also do some good, including strengthening bones, improving sleep, boosting mood, and bolstering the immune system. One study found that sunshine may even be linked to longevity.
“I think people feel afraid of sun exposure, but the key is to find a better balance,” says Dr. Julia Afridi, DO, a Lifeforce Physician board-certified in family and integrative medicine. “Sunlight is a natural, easily accessible, and free resource that can be a tool for better health when utilized appropriately.”
So, how do we capitalize on the benefits of sunshine while minimizing the risks? Read on to learn more about how sun exposure affects the body, how much is enough, and how to have fun in the sun while staying safe.
Health Benefits of Sunlight
1. Turns on the Vitamin D Machine
When you’re out in the sun, UVB rays interact with a protein in the skin called 7-DHC that converts it into vitamin D. But around 1 billion people worldwide are deficient in vitamin D with levels below 30 nmol/L. Increasing vitamin D to optimal levels (the U.S. Endocrine Society recommends a target range of 40 to 60 nmol/L) can achieve a host of health benefits, including:
Stronger bones. Vitamin D helps the body absorb calcium, which leads to nourished and denser bones.
Boosted immune system. Vitamin D helps the body fight viruses. Some medical experts believe it can help stave off heart disease, muscle sclerosis, certain autoimmune diseases, and cancer. However, these observational studies require further research.
Better mental health. Studies suggest elevated vitamin D levels may decrease your risk of depression.
However, the same rays that help our skin produce vitamin D are the ones that cause sunburn, a major risk factor for skin cancer. That's why the American Academy of Dermatology advises against using unprotected sun exposure as the primary method of getting vitamin D, especially since studies have found that people who use sunscreen daily can maintain their vitamin D levels with the help of supplements and through eating fatty fish, such as salmon, mackerel, and tuna.
2. Supports Better Sleep
“Unlike the other benefits on this list, where the sunlight needs to hit your skin, sunlight exposure to your eyes is what helps regulate your circadian rhythm,” says Dr. Afridi. “Your eyes are the only exposed part of your nervous system, and direct interaction with the outside world signals to your system that it's daytime and nighttime.”
Exposing your eyes to morning light (however, don’t look directly at the sun!) tells your body to stop making melatonin, the sleepytime hormone, so it can power up for the day. Then, in the evening, it starts churning out melatonin when it’s time to prepare for sleep.
“Watching the sun rise and set will get you on a regular schedule and sleeping well,” says Dr. Afridi. “We have all this technology, products, and supplements to help us sleep but sometimes it's the most basic things that can have a profound impact. Just get back to nature.”
3. Lifts Your Mood
Being in the sun generally makes people feel good and relaxed, and many scientific reasons help explain this effect. For one, exposure to UVB rays skin produces beta-endorphins, hormones that reduce pain and stress relief.
Sunlight exposure also helps your body produce the neurotransmitter serotonin that gives you energy during the day and enhances your mood. “It's the feel-good hormone,” says Dr. Afridi. “It can help you feel happier.”
The sun is so effective in boosting your disposition that doctors often treat seasonal affective disorder (SAD) and other types of depression with sunlight or a lightbox. However, there are other spectrums of light used in these lamps besides UVA and UVB that also help with depression, says Beth Goldstein, MD, a board-certified dermatologist and co-founder of Modern Ritual.
If you’re more stoked on the real-deal rays, just take note. “The positive effects and the energy I get from being outside is second to none, but when I'm out there, I still have on sunglasses and a hat,” says Dr. Goldstein. “My endorphins may not be as high as somebody out there in a bikini but they’re still high enough and I also want to reduce my risk of skin cancer.” Balance.
4. Dials Down Inflammation
Excessive sun exposure may increase the risk of skin cancer because it suppresses the immune cells that detect and destroy damaged cells. Yet Dr. Goldstein says immune tempering may be beneficial in some overactive immune responses, such as inflammatory skin conditions like psoriasis.
Sunlight might also improve autoimmune diseases such as arthritis and multiple sclerosis (MS). For instance, a pilot study of 20 individuals with the earliest form of MS suggested that sunlight therapy can actually halt or delay its progression.
5. Lowers Blood Pressure
The research is ongoing, but a study at the University of Edinburgh suggests that exposure to UV rays triggers the skin to release a compound called nitric oxide. This compound helps lower blood pressure and support a healthier heart. The researchers say the benefit is such that it lowers the risk of heart attack and stroke.
This helps explain why previous studies have found that while increased vitamin D levels are linked to lower cardiovascular disease, supplements do not have the same effect. This study proves that the body’s production of nitric oxide is separate from vitamin D production.
How Much Sun Is Enough?
Several factors can influence how much sun you need, including your skin tone, medical history, medications you’re taking, and geographical location. Talk to your Lifeforce clinician or healthcare provider to figure out the optimal amount for you.
“Luckily, you don't need that much time outside to get the benefits and you can keep the risk of skin cancer minimal,” says Dr. Afridi. “Cover up more delicate areas like your face and shoulders, and expose your arms and legs.”
Generally, experts recommend 5 to 30 minutes of sunlight a day, depending on your skin tone. People with dark skin need more time to reap the benefits while those with lighter skin absorb rays quickly and have a higher risk of skin damage.
No matter where you land on the scale, it’s critical to remember that, in this case, too much of a good thing can be a really bad thing. Whatever you do, avoid sunburns and tans, which increase your chance of skin cancer and can happen in mere minutes. Some research even suggests that too much sunlight can lower immune system functioning.
To determine the length of time you can stay in the sun without burning, use the UV index, which forecasts the level of solar radiation for any particular location, day, and time. It’ll tell you whether you can safely enjoy being outside and if you need to take any precautions depending on your skin type. “Use it to gauge how covered up you should be because clothing will help you when the UV index is high,” says Dr. Goldstein.
No matter what, ensure you’re protecting your skin if you’ll be out for longer than what’s recommended and always wear sunscreen when outside between 10 a.m. and 4 p.m., when UV exposure is at its highest.
This article was medically reviewed by Julia Afridi, DO, ABIHM Board Certified in Family and Osteopathic Medicine.